Sometimes when ceiling boxes are roughed in, they use x/3 with ground cable so that they can supply 1 switched hot, 1 neural, 1 hot/switched hot, and 1 ground to the ceiling box.
This allows a ceiling fan to be installed in such a way that the fan can be controlled either by a separate switch, or using only the attached pull chain. In this situation the red wire in the cable is usually disconnected and capped at both ends, and is only intended to be connected as needed.
You may be able to verify this by opening the switch box, and verifying the wiring at the switch. If this is the case and the extra hot wire is not needed, it should be disconnected and capped at both ends. Once that's complete, you can move on to determining if you have a proper grounding conductor.
Grounding Conductor
If the building was renovated/built in 2008, it's not likely the circuit does not include an ground conductor. However, there are multiple ways to satisfy the grounding conductor requirement according to NEC 2008 250.118.
- A copper, aluminium, or copper-clad aluminum conductor.
- Rigid metal conduit.
- Intermediate metal conduit.
- Electrical metallic tubing.
- Listed flexible metal conduit meeting specific conditions.
- Listed liquidtight flexible metal conduit meeting specific conditions.
- Flexible metallic tubing meeting specific conditioins.
- Armor of Type AC cable as provided in 320.108.
- The copper sheath of mineral-insulated, metal-sheathed cable.
- Type MC cable where listed and identified for grounding in accordance with specific criteria.
- Cable trays as permitted in 392.3 and 392.7.
- Cablebus framework as permitted in 370.3.
- Other listed electrically continuous metal raceways and listed auxiliary gutters.
- Surface metal raceways listed for grounding.
Checking for a Grounding Conductor
The most accurate way to verify whether or not there a proper ground connected, would be to check for continuity between the junction box and the grounding electrode system. In most situations this is not an option, so another test must be performed.
Checking Continuity to the Grounding Electrode System
To run this test you'll either have to be within reach of; or be able to run a lead to, the grounding bus in the main service panel.
- Set your multimeter to the continuity setting or the lowest
resistance setting.
- Place one lead on the grounding bus bar in the load center.
- Place the other lead on the junction box under test.
If the meter beeps or gives a reading close to 0, the box and the load center are electrically connected. This means there is a proper grounding conductor installed. If the meter does not beep or has a reading of infinity, the box and the load center are not electrically connected. You'll have to install an approved grounding conductor throughout this circuit, if you want proper grounding.
Checking Continuity to a Known Good Ground
If you have a known good ground nearby (from another circuit, for example), you can use this ground to test for an equipment ground at the box in question.
- Set your multimeter to the continuity setting or the lowest
resistance setting.
- Place one lead on the known good ground.
- Place the other lead on the junction box under test.
If the meter beeps or gives a reading close to 0, the box and the known good ground are electrically connected. This means there is a proper grounding conductor installed. If the meter does not beep or has a reading of infinity, the box and the known good ground are not electrically connected. You'll have to install an approved grounding conductor throughout this circuit, if you want proper grounding.
Check Continuity to the Grounded Conductor
If neither of these options are available, the next best option is to check for continuity between the box and the circuits grounded conductor (neutral). These two conductors should be electrically connected (bonded) at the main service panel, so checking continuity between them can (usually) determine if there is an equipment ground.
WARNING: This method relies on the circuit being installed correctly. If the grounded conductor (neutral) is (incorrectly) connected to the grounding conductor anywhere along the circuit, this test may give invalid results.
- Set your multimeter to the continuity setting or the lowest
resistance setting.
- Place one lead on the grounded conductor (neutral).
- Place the other lead on the junction box under test.
If the meter beeps or gives a reading close to 0, the box and the grounded conductor (neutral) are electrically connected. This means there may be a proper grounding conductor installed. If the meter does not beep or has a reading of infinity, the box and the grounded conductor (neutral) are not electrically connected. You'll have to install an approved grounding conductor throughout this circuit, if you want proper grounding.
NOTE:
All continuity testing should be carried out while the circuit is dead. Shut off power to the circuit at the breaker before working on the circuit, and verify the circuit is off using a non-contact voltage tester.
Electricity is dangerous and can lead to property damage, injury, and death. If you do not feel comfortable working with electricity, please contact a qualified Electrician.
These type of boxes usually have 1 or 2 screws going through the bottom into a steel bar that spans between ceiling joists.
I think you are correct that this box is not properly supported.
If you have access from above, you can put a support (2x lumber) across to each joist and then screw through the box into the support.
Options from below only would involve removing the existing box and using one of several replacement boxes. Removing the existing box will involve turning off the power and prying the electrical cable loose from its strain relief. From the looks of the box, it should pull down. Fixture weight will determine which one to use.
The heaviest duty box is one rated for ceiling fans. It uses expandable threaded supports that wedge against the joists side to side. This box would be rated up to 50lbs.
An old work round plastic box has three retractable wings that clamp the box against the drywall. This box is suitable for lighter fixtures, perhaps up to 10lbs. It is very dependant on intact and unbroken drywall for best performance.
Best Answer
If you can get enough access to install a BX connector on that armored cable, and if you can establish that the armor is actually a good protective ground (some armored cable only "floats" electrically), then you may be able to use a "remod box" to connect to the BX and claim your ground from the box. If none of those is true, then you really should do whatever it takes - cut access holes to be covered by the tracklight and install 2x4 remod boxes, whatever - to at the very least finish up that run with NM-B (Romex-type) cable. Given that this is for an overhead tracklight and you may not have any true grounds anywhere on that whole floor, and this house was probably wired long before grounding light fixtures became standard, you're probably legally covered.
I'm not as worried about spark containment as I could be, since the tracklight has its own termination box. Chafing of the wire insulation, though, is a bit worrisome; that's the largest reason for NM-B becoming standard. At the very very least, it'd be good to strip (without splitting) the outer sheath from a length of new NM-B and pull your two individual wires through it.